Greetings,

Recently, I completed setting up an FC2-enabled server as a home
gateway.


Its connection to the Internet is by way of Verizon's PPPoE DSL. The
external Westell modem connects to eth0; the home LAN connects to
eth1.


Everything seems to be communicating correctly. The concern I have
and
the request I make of the list is to review the iptables setting for
the
gateway.


Stock FC2 Iptables looks like this:
root leeloo ~> iptables-save
# Generated by iptables-save v1.2.9 on Sun Aug 29 17:06:53 2004
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [20310127:17271169167]
:RH-Firewall-1-INPUT - [0:0]
-A INPUT -j RH-Firewall-1-INPUT
-A FORWARD -j RH-Firewall-1-INPUT
-A RH-Firewall-1-INPUT -s 127.127.1.0 -p udp -m udp --sport 123 --
dport 123 -j ACCEPT
-A RH-Firewall-1-INPUT -i lo -j ACCEPT
-A RH-Firewall-1-INPUT -i eth0 -j ACCEPT
-A RH-Firewall-1-INPUT -p icmp -m icmp --icmp-type 255 -j ACCEPT
-A RH-Firewall-1-INPUT -p esp -j ACCEPT
-A RH-Firewall-1-INPUT -p ah -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport
25 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport
80 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport
443 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport
21 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport
22 -j ACCEPT
-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
COMMIT
# Completed on Sun Aug 29 17:06:53 2004


I've amended it; the lines I've added are preceded by >>> and ended
w/ <<<:


# Generated by iptables-save v1.2.9 on Sun Aug 29 17:08:40 2004
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [10797:1210790]
:RH-Firewall-1-INPUT - [0:0]
-A INPUT -j RH-Firewall-1-INPUT
-A FORWARD -j RH-Firewall-1-INPUT


-A RH-Firewall-1-INPUT -s 127.127.1.0 -p udp -m udp --sport 123 --
dport 123 -j ACCEPT <<<

-A RH-Firewall-1-INPUT -i lo -j ACCEPT


-A RH-Firewall-1-INPUT -i eth1 -j ACCEPT<<<
-A RH-Firewall-1-INPUT -p icmp -m icmp --icmp-type 255 -j ACCEPT
-A RH-Firewall-1-INPUT -p esp -j ACCEPT
-A RH-Firewall-1-INPUT -p ah -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport
80 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport
443 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport
22 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport
21 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport
25 -j ACCEPT

-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport
53 -j ACCEPT


-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
COMMIT
# Completed on Sun Aug 29 17:08:40 2004


Everything below was added to stock FC2 Iptables settings<<<
# Generated by iptables-save v1.2.9 on Sun Aug 29 17:08:40 2004
*nat
:PREROUTING ACCEPT [11662:691042]
:POSTROUTING ACCEPT [97:5735]
:OUTPUT ACCEPT [96:5659]
-A POSTROUTING -s 192.168.1.0/255.255.255.0 -o ppp0 -j MASQUERADE
COMMIT
# Completed on Sun Aug 29 17:08:40 2004


End addition <<<<
I run a standalone server on an ISP loaded w/ FC2 and running the
stock Iptables
configuration. There doesn't seem to be any security problems.


The biggest hurdle was getting machines on the home network making
requests through the gateway; initially, no web, ssh, or ftp
requests were possible using domain names. They could only
be made using explicit ip addresses.

Once I added
-A RH-Firewall-1-INPUT -i eth1 -j ACCEPT<<<
service requests to the internet using domain names began to work
correctly.

My concern is how exposed/vulnerable is the above gateway
configuration?

Much thanks for your help!


Max Pyziur
pyz brama com

-- end of forwarded message --